Expansion tank

Abstract

An expansion tank ( 1 ) which is intended to be connected to a pipe system which is filled or is to be filled with liquid, comprises a substantially closed tank ( 2 ) having at least a first connection opening ( 6 ) for connection to a liquid pipe, a second connection opening for connection to a source of pressurized gas ( 14 ), and an element ( 8 ) which can move inside the tank and is designed to move with the interface ( 11 ) between liquid ( 9 ) and gas ( 10 ) in the tank. The tank is provided, at the location of the second connection opening, with a valve assembly ( 7 ) which can open and close the second connection opening and can be actuated by the movable element ( 8 ) in the tank.

1. An expansion tank which is intended to be connected to a pipe system which is filled or is to be filled with liquid, comprising a substantially closed tank having at least a first connection opening for connection to a liquid pipe, a second connection opening for connection to a source of pressurized gas, and an element which can move inside the tank and is designed to move with the interface between liquid and gas in the tank, the tank being provided, at the location of the second connection opening, with a valve assembly which can open and close the second connection opening and can be actuated by the movable element in the tank. 
   
   
     2. The expansion tank of  claim 1 , in which the source of pressurized gas is a reservoir which is connected or is to be connected to the second connection opening and comprises a stock of pressurized gas. 
   
   
     3. The expansion tank of  claim 2 , in which the reservoir containing pressurized gas is an integral part of the expansion tank and is separated from the actual expansion tank by a partition wall in which the second connection opening is incorporated. 
   
   
     4. The expansion tank of  claim 2 , in which the reservoir containing pressurized gas is a separate reservoir. 
   
   
     5. The expansion tank of  claim 4 , in which the reservoir containing pressurized gas is or can be accommodated in a space which is at least partially surrounded by a wall part connected integrally to the wall of the expansion tank and which is separated from the actual expansion tank by means of a partition wall in which the second connection opening is accommodated. 
   
   
     6. The expansion tank of  claim 5 , in which the partition wall is provided, at the location of the second connection opening, with a connecting member for producing a connection between the interior of the reservoir containing pressurized gas and the second connection opening when the reservoir containing pressurized gas is being placed in the space which is intended for it. 
   
   
     7. The expansion tank of  claim 6 , in which the reservoir containing pressurized gas is a thin-walled disposable reservoir, and the connecting member comprises a puncturing member for puncturing the wall of the reservoir containing pressurized gas when it is being placed in the space which is intended for it, in such a manner that a connection is produced between the interior of the reservoir containing pressurized gas and the second connection opening. 
   
   
     8. The expansion tank of  claim 4 , in which the reservoir containing pressurized gas is or can be connected to the tank via a connection piece which is fitted to the tank on the outer side at the location of the second connection opening. 
   
   
     9. The expansion tank of  claim 4 , in which the valve assembly is provided with means for preventing gas from flowing out of the tank when the reservoir containing pressurized gas is not connected to the tank.